Mold former



Nov. 20, 1962 E. A. STEINBOCK ETAL 3,

MOLD FORMER Filed Dec. 3, 1954 2 sheets sheet l I I7 /5 I7 I J I I 2 2 0 3 l INVEN TOR.

United States Patent Ofifice Efiddfid Patented Nov. 20, 1962 3,064,309 MQLD FORE ER Edmund A. Steinhock, Robert Neirnan, and Edmund A.

Steinbeck, in, Louisville, Ky; said RohertNeiman and saidEdmund A. Steinbeck, .lxu, assignors to said Edmund A.'Steinbock FiiedDec. 3, BS4, Ser. No. 472,894 Claims. {*Tjl. 13-343 This invention relates to improvements in a mold former'wherein the mold during formation is unrestricted as far as expansion is concerned.

The 'title "mold former as applied to the device of the present invention is similar to, in so far as the production of a casting mold is concerned, the well known casting ring or flash, particularly such as are used in the practice of mechanical dentistry.

In the past, casting molds, particularly as used in dentistry,'utili2ed a sprue pin carrier and crucible former to which was removably attached a sprue pin carrier, usually, a-dissipable pattern and which sprue pin and pattern 'were'encircled by a metal sleeve, called a casting ring, and removably attached to the sprue pin carrier and crucible former.

This assembly of parts, together, constituted the mold former since the ring, metal sleeve, was filled with an investment material that fully and completely covered the inner surface of the sprue pin carrier and mold former and completely encased the sprue pin and pattern.

The investment material, a relatively fluid modified plaster of Paris composition, upon setting has the property of expanding, a property dependent upon to, in part, compensate for the metal shrinkage in the casting eventually formed or produced by the mold.

It has been found that to encase the mold in a metal sleeve or ring the proper and uniform expansion of the investment material was interfered with resulting, sometimes, in castings of smaller dimensions than desired. To compensate somewhat for the interference of the solid encasing casting sleeve or ring the said sleeve was lined with relatively soft material, such as sheet-asbestos, in either a dry or wet stage.

Theexpansion of investment material is found dependent upon the ratio of the dry 'powder'to the water used in mixing the same, it being borne in mind that this ratio must be within reason to produce a plastic mass that can be worked in encasing the pattern and in forming the mold. In order to insure sufiicient' expansion in the mold, the said'mold was subjected to a water bath, that is, the mold assembly-along with the investment after being poured into the ring was immersed in Water for a given period of time which thereby changed the ratio of the free waterto the solid portion of the mold, so that the mold could absorb all of the water it desired and thereby expand to the limitof expansion'of' its composition. This expansion, however, was interfered with by'the non-yielding character of the encircling metallic sleeve or ring.

Furthermore, thewater bath, upon supplying an unlimited amount of additional water generally afiected the'expansion 'of the investment composition to the same degree so that the operatorhadnomethod of varying the amount of expansion should he desire to do so'to' compensate for the various classes of castings.

Bythe present invention, 'there is provided a mold former which inno wise interfere 'withthe expansion of "themold and provides a rnechanism whereby controlled amounts of liquid may be snppliedtothemold after the mold former has been filled with the investment material and therefore can control the expansion 'of the said mold and particularlythe casting cavity therein.

It is, therefore, the principal object of the present inven- 2 tion to provide a mold former which will not interfere, inhibit or prevent the mold from expanding during the setting thereof.

Another objectofthis invention is the provision of a mold former for accomplishing the foregoing object that will operate on each-successive moldin the same manner and without the use of extraneous material which is dependent upon the human element as to the amount and condition of use.

Another object of this invention i the provision ofa mold former, that will accomplish the foregoing objects, that is economical to produce and therefore acquire.

it is also an object of this invention to provide an improved mold form'er for the carrying forward of .the method of producing molds in which the amount of added liquid is-meticulously controlled.

A still further object of this invention is the provision of an improved method of forming-casting molds and wherein the expansion of said molds is controlled by the addition of definite and fixed amounts of additional liquid.

Other objects and advantages of the present invention will be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings formin a part thereof, and it is-to he understood that any modifications may be made in the exact .structural'details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

In the drawings:

PEG. 1 is an elevational view of the improved mold former of the present invention.

FIG. 2 is atop plan view of the mold former of FIG. 1.

FIG. 3 is a vertical sectional view through the mold former of FIG. 1 as seen from line 33 of said FIG. '1.

1G. 4 is a vertical sectional'view'through the mold former showing the same in the second step in'use in the production or formation of a mold.

FIG. 5 is a sectional view of the mold former similar to FIG. 4 showing the sprue pin and pattern in operative position.

FIG. 6 is a top plan view of the mold former in the condition as seen in FIG. 5.

FIG. 7 is a perspective view of a clamp for retaining 'the mold-former in its position of FIG. 5 while the sprue former and pattern are being mounted in operative vposition with respect thereto.

FIG. 8 is a view of the mold former in condition to have the cementitious mas placed therein to encase the pattern and its sprue forming pin.

FIG. 9 is a top plan view of an investment mixer with which the mold forming device of the present invention may be employed.

FIG. 10 is a vertical sectional view through theiinve'stment mixeras seen from line 10-10 on FIG. 9.

FIG. 11 is a vertical sectional view of the improved mold former of the present invention in condition to have added thereto controlling amounts of additional liquid in the carrying forward of the method of producing a casting mold.

FIG. 12 is a chart graphically'setting forth the percent of expansion of the mold as different amounts or quantities of liquid is supplied to the mold.

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts.

The mold former disclosed in this application is an improvernent on the disclosure in the pending application of Edmund A. Steinbock, Charles Armbrecht, and Edmund A. Steinbeck, In, filed April 23, 1951, and entitled Investment Mixer, under Serial Number 222,372, now Patent No. 2,696,022.

Specifically the mold former of the present invention comprises a base member, indicated in its entirety by the reference numeral 15, which in the past has constituted the sprue pin carrier and crucible former and while it may be formed of any suitableor desirable material, is preferably formed of rubber and comprises a body member 16 having a rim 17. Centrally of the body member, it is thickened to form a truncated cone 18 which forms, in the mold itself, the crucible for the molten metal to be directed into the casting cavity. Inwardly of the rim 17, there is provided a skirt or sleeve 19 which is quite thin in cross section in the nature of a sixty-fourth of an inch. It should be noted that this designated thickness of the skirt or sleeve wall is for mold formers for molds that are used in the dental field and in industry where intricate and small castings, in the nature of dental castings, are made. It is to be understood that this wall thickness may be increased. upon the use of a mold former in industry where larger molds are to be made and are employed. It is to be understood that the said skirt or sleeve '19 is to be flexible and expandable to the point where, while it will contain the plastic investment material in its desired shape or form, it will not appreciably prevent expansion of'the said investment material during the time it is setting, or as will later be made clear, is having added thereto additional liquid.

The sleeve or skirt 19 is inwardly spaced from the rim -17 to provide a recess 29 entirely therearound and which extends into the body member 17 for a purpose which will later be made clear. The flexible and expandable rim or skirt 19 is provided at its upper end with a slightly thickened and outwardly projecting rim 21 and is further provided at its lower end With an inwardly projecting thickened band or rib 22. The rib or band 22 is located intermediate the upper and lower ends of the recess 20 and is preferably near the lower end of said recess. 7

Since, as will later be made clear, the mold former may, and preferably will, be used with a vacuum mixer that sets up an exhausting pressurewithin the sleeve or ring 19 and against the sprue pin carrier and crucible former, the said body portion 16 is recessed inwardly of its bottom,

takes the form of sleeve 33 having an exterior diameter to very closely slide into the interior of skirt or sleeve 19, whereupon a downward rolling movement of the sleeve 19 may be eifected by the thumb and fingers against said core, which, commencing with its rim 21, will result in a tight roll 32 of the sleeve at the base thereof.

The skirt or sleeve 19 after being rolled, as at 32, upon release of pressure thereon, will return to its normal position as illustrated in FIGS. 1 and 3, wherefore itis. necessary to retain the said sleeve of its roll during the placement of the sprue pin 29 and pattern 31. Any suitable or desirable means may be employed for so retaining the roll 32, such as the simple holding clamp illustrated in FIGS. 4 to 7, inclusive, and indicated in its entirety by the reference numeral 34a.

This holding clamp may be formed of sheet material such as plastic or metal having an inherent springguality and comprises a base member 34 which underlies the sprue pin carrier and crucible former lower surface as as at 23, and has fitted therein a metal plate 24 to prevent distortion in said base 15 while under said exhausting pressure. The metal plate 24 is retained in operative position by having its peripheral rim 25 embedded in the base material and said rim being overlayed bythe base inwardly projecting lip 26.

The inwardly projecting or truncated cone portion 18 of the base 15 is provided centrally thereof with a socket or pocket 27 into which the lower end 28 of a sprue pin 29 is secured by any suitable or desirable means, that used in dental practice being soft wax and indicated in the drawings by the reference numeral 30. The sprue pin 29 carries at its other or outer end a pattern 31, disclosed in the drawings as a disc but which in practice would take the form of the desired castings, which, again, in the dental field, would be a dental restoration of some form or other. a

y It will be understood, that, with the mold former in its position as illustrated in FIG. 3, it would be next to impossible to'properly fasten the sprue pin 29 and its pattern 30, wherefore the said rubber sleeve or skirt 19 is rolled on itself down against the uppersurface of the base 15, and which is against the upper surface of the rim 17, as illustrated in FIGS. 4 and 5 and indicated by the reference numeral 32. It has been found that by grasping the thickened end or rim 22 of the skirt or sleeve 19 between the fingers and thumbat two diametrically op- Iposite points, the said sleeve canbe rolled from its upstandingposition in FIGS. 1 and 3 to its tightly rolled position 32 in FIGS. 4 and 5. However, to assist in this rolling of the sleeve 19, use is made of a temporary and removable solid core, illustrated in phantom lines in FIG. 3 and solidline FIG. 4, and which core conveniently illustrated in FIGS. 4 and 5. Overlying the said base 34, and in spaced relation thereto, is the hold down or clamp arm 35 having a semi-circular cut out 36 to straddle the core sleeve 33 when mounted in operative position. The cut out 36 also permits a clearance to the upper side of. the said sprue pin carrier and crucible former so that the sprue pin 29 may be properly positioned within the socket 27 and the securing medium or wax 30 disposed in said socket. The cut out 36 results in the clamp portion 35 having arms 37 and 38 which engage with the roll 32 at substantially diametrically opposite points for thereby preventing any loss in the roll 32 by preventing any portion of the roll from tend} ing to unroll or open up. The clamp portion 35 and the base 24 are connected with one another by an upstanding end 39 which is formed to a heighth equal to the heighth of the sprue pin carrier and crucible former plus the heighth of the roll 32 upwardly 0f the upper surface of rim 17. V

In practice the said roll retaining clamping device is applied prior to the removal of the core sleeve 33 as clearly illustrated in FIG. 4 and after the application of said clamp device the core sleeve is removed whereupon the sprue pin 29 with its attached pattern 31 are secured or waxed into position by the securing medium 30 as illustrated in FIG. 5

After the sprue pin 29 and pattern 31 have been sesleeve is automatic, that is, this unrolling is a self inherent feature and thereby prevents any possible damaging contact of the sleeve or skirt with the pattern. The mold former is now ready to have deposited therein the cementitious investment material, for, as. above noted, completely encasing the pattern 31 and the portion of the sprue pin 29 exposed above the sprue pin carrier and crucible former.

It will be appreciated that the skirt or sleeve 19 is ex: tremely flexible and while the cementitious investment material is fluid and readily fiowable, is nevertheless viscous and requires urging to enter and fill the said skirt or sleeve 19. The said skirt or sleeve. will be distorted during the said filling unless extreme care is exercised.

In order to give stability to the said skirt or sleeve 19,

while the investment material is being flowed thereinto, use is made of a ring, to all intents andpurposes similar.

to the casting ring above referred to. This ring, illus-- trated in FIG. 8 and indicated by the reference numeral I At), has an interior diameter to very closely receive the exterior diameter. of the skirt or sleeve 19 and said sleeve 40 is of an exterior diameter, particularly at its lower end, to very closely engage the inner surfaces of the recess 20, formed in the sprue pin carrier and crucible former between the rim 17 and outer surface of the said skirt or sleeve 1?. The said ring 40 in being pressed into the recess 20 is engaged by the outwardly projecting enlargement or rib 22, within said recess 20, for efiecting a secure connection between the parts and at the same time for sealing the ring to the sprue pin carrier and crucible former for a purpose subsequently to be described.

In forming a mold the cementitious material may be manually poured from a mixing cup or vessel into the mold former, such as when assembled and as illustrated in FIG. 8, or preferably the said mold former may be attached to a vacuum mixing device, such as illustrated in FIGS. 9 and 10, and which mixing device forms the subject matter of and is clearly illustrated in the pending application for patent of Edmund A. Steinbock, Jr., and Robert Neiman, Serial No. 255,704, filed November 9, 1951, now Patent No. 2,777,177.

In the event that the process of filling the mold forming device is by the hand method of manually flowing the investment material from the mixing cup or vessel, it is generally desirable to first paint or coat the pattern 31 and the portion of the sprue pin immediately adjacent thereto by a cementitious investing material, and which is illustrated in phantom lines at 41 in FIG. 5. It should be noted that with the mold former of this invention in the condition as illustrated in Fig. 5 and with its skirt or sleeve 19 in the roll 32 and the roll retained by the clamping device 34a, the said painting, or the application of the investment 41, can be readily and eflectively accomplished.

The vacuum mixing device, while fully and completely illustrated and described in the above identified Steinbock and Neiman application, briefly is as follows:

This mixer comprises a cup-like m'ming member or container 42 in which the ingredients are mixed with said container or member 42 having interiorly thereof a mixer blade or paddle 43 secured to and carried by a driving shaft 44. The driving shaft 44 is rotatably mounted in a sleeve or bushing 45 pressed into or cast within a hollow upstanding post or boss 46 from the container or member 42 closing lid or cover 47. In other words, the cup or mixing container 42 is closed by the cover or lid 47 in which is journaled a shaft 44 that carries at its lower end and within the cup or container 42, a paddle or mixing blade 43.

The cover or lid 47, to one side of the cylindrical post or boss 46, is provided with an upstanding lug through which is formed an aperture or bore 48 communicating with the interior of the mixing cup or container and which bore 48 receives the end of a coupling or nipple 49 which in turn has connected therewith one end of a flexible conduit or hose 59 and which flexible conduit or hose 50 has its other end connected to an exhaust pump, or the like, not shown in the drawing.

The cover or lid 47 on the other side of the post or boss 46 is provided with an extension 51 counterbored to receive the lower or inner end of the mold former assembly, such as illustrated in FIG. 8. The interior of the mold former assembly is in communication with the interior of the mixing cup or container 42 through an aperture 52 formed through the lid or cover 47.

Upwardly of the busing 45 the mixing blade or paddle shaft 44 is provided with a threaded reduced portion 53 on which is threaded a shaft driver 54 having in its other end a socket 55 transversely of which is formed a kerf or slot 56. The kerf or slot 56 is adapted to receive a driving pin 57 extending from the end of a power driven shaft 58, such as a motor shaft or the shaft of a dental lathe.

As was noted above the extension or boss 51 is counterbored and is provided with a base 59 as well as with intermediate seats which may be designated as a lower intermediate seat 60 and an upper intermediate seat 61. Above the upper intermediate seat 61 is a seat 62 on which is disposed on a guide ring 63 that has an internal diameter substantially equal to the external diameter of the mold former outer ring 40.

The mold former must be sealed against leakage during the evacuation of the mixing cup and parts connected therewith and while any suitable or desirable sealing means may be employed, an efiective one, as illustrated in the drawings, comprises an Oring 64 which has an internal diameter slightly less than the external diameter of the ring 4%) and has an external diameter slightly greater than the diameter of the counterbore immediately above the lower intermediate seat 60. As pointed out in the above identified applications, the O-ring 64 is normally resting on the upper intermediate counterbore seat 61 and upon the insertion of the mold former within the counterbore the said O-ring is rolled from the said counterbore seat 61 to the counterbore seat 64 and thereby the said G-ring is compressed and elongated, as illustrated in FIG. 10, between the ring 46 and wall of the counterbore and effectively seals the mold former assembly within the said counterbore. The mold former assembly upon reaching its final position has the outer end of the ring 40 against the counterbore base 59 and the sleeve 19 is loosely against the inner surface of said ring 46 so that no deformation of the said skirt or sleeve 1? is efiected while under the sub-atmospheric pressure as effected by the exhaust pump through the hose or flexibl conduit 50. The reinforcing plate 24 of the sprue pin carrier and crucible former also prevents any deformation of the body portion 16 of the base 15, and thereby prevents the breaking of the seal between the end of the ring 40 within the groove or channel 28.

The ingredients in the mixing cup 42 are mixed by the mixing blade or paddle 43 and as soon as said mixing has been completed the mixer is disconnected from the driving shaft 58 and the same turned end for end with the mold former base 15 having the lower surface of its body member 16 on a vibrator so that the mixed ingredients from the mixing cup 42 are directed into the mold former assembly with said vibrator insuring the complete filling of the mold former, all as is clearly and specifically set out in the above identified applications.

The filled'mold former assembly is removed from the mixer by withdrawing the same from the counterbore and the guide ring 64-; it being understood that the vacuum pump to the flexible conduit or hose 50 having previously been stopped or disconnected. Upon removal of the mold former assembly from the said counter bore, the casting ring 49 is stripped from the exterior of the flexible sleeve or skirt 19, and the said mold former with its investment material then further processed either by allowing the same to set and harden in its present condition in the atmosphere, or by subjecting it to the usual water bath, or by having added thereto further and controlled quantities of liquid, generally, water.

If either of the first two methods, allowing the mold to set and harden in the atmosphere or subjecting the same to the Water bath treatment, nothing further is done to the mold. If, however, controlled amounts of water are to be added then the mold is prepared to receive said additional liquid or water, since the said mold is filled to the upper edge of its sleeve or skirt a reservoir for this added water must be provided.

Accordingly, the mold former has added to its upper end a reservoir forming device formed of flexible and inflexible material and which comprises a sleeve 65 having radially projecting from intermediate its ends a radial flange 66. The sleeve 65 has an exterior diameter to slide Within the mold former flexible skirt or sleeve 1? and the portion, indicated in the drawings by the reference numeral 67, that projects below the said flange 66 is then inserted into the upper end of the said mold former flexible skirt or sleeve 19, since the investment composition at this time is soft and fluid no appreciable difliculty is encountered in inserting the said reservoir sleeve portion 67 into the mold, it being understood that if desired the exterior diameter ofsaidreservoir sleeve portion 67 may be tapered'inwardly to assist in the placement of said reservoir sleeve, with the reservoir sleeve in the upper end of the mold former flexible skirt or sleeve the portions thereof represented by the radial flange 66 and the portion of the sleeve 68. above the radial flange form the reservoir above the upper surface of the investment material or mold proper, as Clearly illustrated in FIG. 11. The reservoir is indicated in the drawings by the reference numeral 6? and it is into this reservoir that the added liquid, water, is placed.

It is to be understood that the investment composition consists ofp'owder in the nature of plaster of Paris havirig incorporated therein control ingredients for effecting a setting" expansion, a thermal expansion, and an accelerator or retarder for controlling the setting time. This powder is mixed with a liquid or water in the desired proportion for forming the desired mold but, due to various factors to which the mold is subsequently subjected, such as the casting temperature of the metal to be cast therein, as well as the desired eventual expansion of the mold due to the particular metal used, itmay be desirable to increase the setting expansion and it has been found that this setting expansion is controllable by adding particular amounts of water to the mold before it finally sets.

The chart in FIG. 12 indicates the typical amount of said Volumetric expansion as affected by the percentage of added water. This expansion would amount to approximately one and eight tenths (1.8%) percent upon the addition of one (1%) percent of water while two (2%) percent of water added would give a volumetric expansion of approximately two and eighty five hundredths (2.85% percent, and so on as clearly and graphically illustrated. The reservoir 69 at the upper end of the mold former is utilized for receiving these controlled added amounts of Water.

It will be readily appreciated that the mold former of the present invention due to the readily flexible encircling skirt or'sleeve'i9 does not appreciably interfere with this volumetric expansion since the said skirt or sleeve will yield under the least pressure and will offer no resistance to the mold expansion even at and well above the upper limit of the said expansion.

After theadded water has been absorbed by the investment composition it is allowed to harden or set, and the same thing holds true for the mold while in the water bath for the required or desired period of time, if the water bath method is being employed.

As soon as the cementitious mold has set, or when it is desired to subject the cementitious mold to the further step of removing the wax patternthereform, the said mold formeris removed from the cementitious mold which is conveniently accomplished by rolling the flexible skirt or sleeve 19 on its upper ridge or rim 21, in the same manneras above set forth, until the roll 32 is on the upper face of the base rim 17, whereupon the cementitious mold is eased from the surface of the crucible forming truncated cone 18 with the sprue pin projecting from the mold.

The cementitious mold is now processed in the usual manner for producing a casting.

What is claimed is:

l. A mold former of the class described comprising a base, means on said base temporarily securing a pattern thereto to upstand therefrom, and a flexible and expansiblesleeve integral with said base to upstand therefrom and of an internal diameter and a height to completely encircle and be above said pattern.

2. A mold former of the class described comprising a base, means on said base temporarily securing a pattern thereto to upstand therefrom, said base being formed of deformable rubber, a reinforcing plate carried by said base for rigidity, and a flexible and expansible sleeve integral with said base to upstand therefrom and of an internal diameter and a heighth to completely encircle and be above said pattern.

base on which a pattern may be temporarily secured to upstand, a. flexible sleeve integral with said base to upstand therefrom and of an internal diameter and a heighth to completely encircle and be above said pattern, said base interiorly ofthe sleeve being provided with a socketthrough which the pattern is secured thereon, said sleeve being adapted to be rolled base to permit. placement of the pattern, and means for retaining the said sleeve in its-rolled position during said pattern. placement.

5. A mold former of the class described comprising a base having a bottom surface and an upper surface, a flexible and expansible sleeve. integral with said base upwardly of the upper surface of the base, said base having a groovedownwardly of its upper surface around the lower end of" the said flexible sleeve, and aring within said groove to upstand therefrom exteriorly of the sleeve.

6. A mold former of the class described comprising a base having a bottom surface and an upper surface, a flexible and expansible sleeve integral upwardly of the upper surface. of the base and having a thickened. upper end, said base having a groove downwardly of its upper. surface around the lower end of the said sleeve, and a ring. within said groove to upstand therefrom exteriorly of the sleeve with said. sleeve thickene'd' upper end and the free. end .of the ring in substan: tially the same place. V

7. A mold former of the class described comprising a base having a bottom surface and an upper surface, a

flexible and expansible sleeve integral with said base upwardly of the upper surface of the base, said base having a groove downwardly of its upper surface around the lower end of the said sleeve, said base upper surface, within the sleeve, having formed therein a down-:

wardly projecting socket, and a ring within said groove to upstand therefrom exteriorly of the sleeve.

8. A mold former of the class described comprising .a base havinga bottom surface and an upper surface, a flexible and expansible sleeve integral with said base upwardly of the upper surface of the base, said base having a groove downwardly of its upper surface around the lower end of the said sleeve, said base having its upper surface, within the sleeve, formed as a truncated cone with the sides tapering from said base toward the center of the sleeve and a socket formed downwardly of the upper end of said truncated cone, and a ring within said groove to upstandtherefrom exteriorly of the sleeve.

9. A mold former of the class described comprising a base having a bottom surface and an upper surface, a flexible and expansible sleeve integral with said base upwardly of the upper surface of the base, said base having a groove downwardly of its upper surface around the lower end of the said sleeve, said base having its upper surface, within the sleeve, formed as a truncated cone with the sides tapering from said base toward the center of the sleeve and a socket formed downwardly of the upper end of said'truncated cone, said flexible sleeve having its free end thickened to provide a rim around which the sleeve may be tightly rolled onto the upper surface of the base, and removable means for retaining the sleeve in its rolled position.

10. A mold former of the class described comprising a base having a bottom surface and an upper surface, a flexible sleeve integral with the base upwardly of the upper surface of the base, said base having a groove exteriorly on itself toward the i with said base" downwardly of its upper surface around the lower end of the said sleeve, said base having its upper surface, Within the sleeve, formed as a truncated cone with the sides tapering from said base toward the center of the sleeve and a socket formed downwardly of the upper end of said truncated cone, said flexible sleeve having its free end thickened to provide a rim around which the sleeve may be tightly rolled onto the upper surface of the base, and a claznp comprising a base underlying the mold former bottom surface and spring clamp arms overlying the flexible sleeve roll holding same in its rolled position.

11. The method of forming a cementitious casting mold comprising the utilization of a sprue pin carrier and crucible former having integral therewith a flexible sleeve, roliing said flexible sleeve on itself to a position on the upper surface of the sprue pin carrier and crucible former, securing a sprue pin and pattern to the said sprue pin carrier and crucible former at a point within the flexible sleeve roll, unrolling the flexible skirt or sleeve to its normal position to encircle and extend above the pattern, and filling the said flexible sleeve with cementitious mold forming material.

12. The method of forming a cementitious casting mold comprising the utilization of a sprue pin carrier and crucible former having integral therewith a flexible sleeve, rolling said flexible sleeve on itself to a position on the upper surface of the sprue pin carrier and crucible former, securing a sprue pin and pattern to the said sprue pin carrier and crucible former at a point Within the flexible sleeve roll, unrolling the flexible sleeve to its normal position to encircle and extend above the pattern, filling the said flexible sleeve with cementitious mold forming material, applying a short sleeve to the upper end of said flexible sleeve after the filling thereof with cementitious mold forming material to provide a reservoir for liquid, and supplying the liquid to the reservoir.

13. The method of forming a cementitious casting mold comprising the utilization of a sprue pin carrier and crucible former having integral therewith a flexible sleeve, rolling said flexible sleeve on itself to a position on the upper surface of the sprue pin carrier and crucible former, securing a sprue pin and pattern to the said sprue pin carrier and crucible former at a point within the flexible sleeve roll, unrolling the flexible skirt or sleeve to its normal position to encircle and extend above the pattern,

attaching an inflexible ring to the sprue pin carrier and crucible former to upstand therefrom exteriorly of the flexible sleeve, and filling the said flexible sleeve with cementitious mold forming material.

14. The method of forming a cementitious casting mold comprising the utilization of a sprue pin carrier and crucible former having integral therewith a flexible sleeve,

rolling said flexible sleeve on itself to a position on the upper surface of the sprue pin carrier and crucible former, temporarily retaining the flexible sleeve in its rolled position by removable retaining clamp means, securing a sprue pin and pattern to the said sprue pin carrier and crucible former at a point within the flexible sleeve roll, painting the pattern with a cementitious mold forming material, unrolling the flexible sleeve to its normal position to encircle and extend above the pattern, and filling the said flexible sleeve with cementitious mold forming material.

15. The method of forming a cementitious casting mold comprising the utilization of a sprue pin carrier and crucible former having integral therewith a flexible sleeve, rolling said flexible sleeve on itself to a position on the upper surface of the sprue pin carrier and crucible former, temporarily retaining the flexible sleeve in its rolled position by removable retaining clamp means, securing a sprue pin and pattern to the said sprue pin carrier and crucible former at a point within the flexible sleeve roll, unroliing the flexible skirt or sleeve to its normal position to encircle and extend above the pattern, attaching an inflexible ring to the sprue pin carrier and crucible former, and filling the said flexible sleeve with cementitious mold forming material.

References Qited in the file of this patent UNITED STATES PATENTS 1,425,550 Spiro Aug. 15, 1922 1,637,564 Gillette Aug. 2, 1927 1,715,465 Meyer et al June 4, 1929 1,796,470 Meyer Mar. 17, 1931 2,187,260 Brandenburg Jan. 16, 1940 2,188,915 Mizzy et al Feb. 6, 1940 2,274,186 Brace Feb. 24, 1942 2,315,748 Thompson Apr. 6, 1943 2,507,867 Pomes May 16, 1950 2,602,310 Hansen July 8, 1952 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,064,309 November 20 1962 Edmund A, Steinbock et alo It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 7, line 66, for height read heighth column 8, line 37, for "place" read plane column 9, lines 19 and 44, and column 10, line 28, strike out "skirt or, each occurrence,

Signed and sealed this 3rd day of September 1963 (SEAL) Attest:

ERNEST w. SWIDER DAVID LADD Attesting Officer Commissioner of Patents 

